获取当月的第一天和最后一天

Question

我这里有2个datepicker用于开始日期和结束日期 。

我怎样才能获得当月的第一天和最后一天

rdpStartDate.SelectedDate = DateTime.Now;
rdpEndDate.SelectedDate = DateTime.Now;

Answer 1

DateTime now = DateTime.Now;
var startDate = new DateTime(now.Year, now.Month, 1);
var endDate = startDate.AddMonths(1).AddDays(-1);

Answer 2

var now = DateTime.Now;
var first = new DateTime(now.Year, now.Month, 1);
var last = first.AddMonths(1).AddDays(-1);

您还可以使用DateTime.DaysInMonth方法：

var last = new DateTime(now.Year, now.Month, DateTime.DaysInMonth(now.Year, now.Month));

Answer 3

var myDate = DateTime.Now;
var startOfMonth = new DateTime(myDate.Year, myDate.Month, 1);
var endOfMonth = startOfMonth.AddMonths(1).AddDays(-1);

这应该给你你需要的东西。

Answer 4

试试这个已经用c＃构建的代码

int lastDay = DateTime.DaysInMonth (2014, 2);

第一天总是1。

祝好运！

Answer 5

受Chris Shao的回答启发，我为这两个值创建了函数：

private DateTime FirstDayOfMonth()
{
    return new DateTime(DateTime.Now.Year, DateTime.Now.Month, 1);
}

private DateTime LastDayOfMonth()
{
    return new DateTime(DateTime.Now.Year, DateTime.Now.Month, 1).AddMonths(1).AddDays(-1);
}

Answer 6

string firstdayofyear = new DateTime(DateTime.Now.Year, 1, 1).ToString("MM-dd-yyyy");
string lastdayofyear = new DateTime(DateTime.Now.Year, 12, 31).ToString("MM-dd-yyyy");
string firstdayofmonth = new DateTime(DateTime.Now.Year, DateTime.Now.Month, 1).ToString("MM-dd-yyyy");
string lastdayofmonth = new DateTime(DateTime.Now.Year, DateTime.Now.Month, 1).AddMonths(1).AddDays(-1).ToString("MM-dd-yyyy");